1. Field of the Invention
The present invention relates to an automatic focus adjustment camera that performs focus adjustment of the photographic optical system according to focus detection results in multiple focus detection regions on a photographic screen.
2. Description of Related Art
An automatic focus adjustment camera has been known that performs focus adjustment in multiple focus detection regions established on a photographic screen of a photographic optical system, detects the defocus amount of the photographic optical system in each of the focus detection regions, sets a final defocus amount from among these multiple defocus amounts, and drives the photographic optical system in accordance with this final defocus amount.
However, in conventional automatic focus adjustment cameras, each time focus detection is performed, the focus detection sensors are operated in all focus detection regions simultaneously, the focus detection computation is performed with respect to the output obtained from all of the sensors, and the final defocus amount is set after the defocus amounts from all of the focus detection regions are computed. As a result, when the length of time it takes for some of the focus detection regions to compute the defocus amount is large, the length of time it takes-to compute the final defocus amount becomes prolonged because of the length of time needed in these focus detection regions, causing the responsiveness of the focus adjustment to diminish.
For instance, when electric charge accumulation type sensors are used as the focus detection sensors, the electric charge accumulation time of the sensors that capture dim subjects is relatively long, so that the time interval in which the final defocus amount is computed increases in response to the electric charge accumulation time of the sensors that capture dim subjects, even when other sensors capture bright subjects.